Integrator with bias compensation (CB20991E)

This circuit was found in a Popular Electronics from the 90's. It can be implemented with equivalent operational amplifiers.

Receiver without Power Supply (CB3838E)
The signal itself captured by the (long) antenna serves to feed this simple experimental circuit....
Voltage Level Switch (CB21463E)
This voltage level-triggered circuit was found in a 1969 Ferranti English documentation. Modern...
10 W amplifier TDA2006 2 (CB15243E)
This amplifier makes use of a simple 12 to 30 W source, having been found in the SGS manual of...